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Heat Shrink Basics!

Heat Shrink Basics!

Heat Shrink is a common and important part of protecting and providing insulation for cables and wires. Heat shrink can also provide protection against abrasion, chemicals and weather.

Heat Shrink tubing is an expandable plastic sleeve that is designed to shrink when it is heated to wrap around wires. Many people install heat shrink themselves as it is a cheap and easy option that is super easy to fit or install.

There is a wide variety of Heatshrink - Colours, Sizes, Materials and Lengths. 

1) Heatshrink Uses:

  • Cable Protection

  • Mechanical Protection against abrasion

  • Protection against Environmental conditions such as damp, contaminants, light and chemicals

  • Aesthetics and to organise / colour code wires or cables

  • Bundling cables neatly 

2) Shrink Ratio:

The most common heat shrink ratios are 2:1, 3:1 and 6:1. This means that Heat Shrink tubing with a 2:1 ratio will shrink down to  half of it's expanded diameter.

3) Selecting the Correct Size:

Our heat shrink is measured and specified by the preshrink internal diameter  and NOT the flat width of the heat shrink which is different! This is an important difference and is a common mistake we frequently hear.

It is generally advised that the heat shrink selected should be 1.5 x larger than the items or wire it is to be fitted over.


4) Materials:

Most Heatshrinks are either PVC or Polyolefin with the primary differences being cost and working temperature.

PVC is generally cheaper than Polyolefin however the Polyolefin tubes tend to have a wider operating range. Dependent on the intended use, PVC or Polyolefin may be appropriate.

Adhesive lined Heatshrink is available which has an interior adhesive that melts upon application of heat to form a protective waterproof seal. This therefore provides extra protection when sealed from environmental conditions such as moisture or contaminants.



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Mike - December 24, 2023

It would useful to add the recommended temperature to the heatshrink guide,


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